1. Field of the Invention
The present invention relates to an electronic apparatus, such as a portable computer, having a keyboard in its main body, in particular, a structure for fixing a keyboard on a main body.
2. Description of the Related Art
Electronic apparatuses such as portable computers include a main unit having a keyboard. Standard keyboards have a keyboard base, and a plurality of key tops arranged on a top surface of the keyboard base. In keyboards of this kind, the sizes of the keyboard bases and key tops are standardized. Therefore, standardized keyboards can be used for different types of portable computers, and thereby the cost of the portable computers is reduced.
Each of Jpn. Pat. Appln. KOKAI Pub. No. 2002-236523 (Prior Art I), Japanese Patent No. 3394818 (Prior Art II) and Japanese Patent No. 3382073 (Prior Art III) discloses a portable computer having a keyboard on a top surface of its main body.
According to Prior Art I, a keyboard base of a keyboard is detachably supported by a keyboard support portion formed in a top surface of a main body. The keyboard support portion is a recess opened in the top surface of the main body and having a size into which the keyboard base is tightly fitted. The keyboard base has a front edge having a plurality of engaging pieces, and a rear edge having a plurality of mounting pieces. The engaging pieces are detachably engaged with the keyboard support portion. The mounting pieces are fixed to the keyboard support portion by respective screws.
In Prior Art II, a main body comprises a lower case and an upper case. The upper case is divided into a front portion and a rear portion. The rear portion of the upper case has a keyboard support portion into which a keyboard base of a keyboard is fitted. The keyboard base has a front edge having a plurality of first engaging projections, and a rear edge having a plurality of second engaging projections. The first engaging projections are configured to be held between the front portion and the keyboard support portion, when the front portion of the upper case is mounted onto the lower case. The second projections are fixed to the keyboard support portion by respective screws.
Further, in Prior Art III, a keyboard support portion and a parts-mounting part are formed in a top surface of a main body. The keyboard support portion is a recess into which a keyboard base of a keyboard is fitted, and is disposed in front of the parts-mounting part. A front edge and a rear edge of the keyboard base are detachably engaged with the keyboard support portion. The parts-mounting part supports parts such as a speaker. The parts-mounting part is covered with a detachable top cover. The top cover has an engaging wall which enters an rear end of the keyboard support portion. The rear edge of the keyboard base is held between the engaging wall and the keyboard support portion.
As described above, in each of Prior Arts I to III, the keyboard is fixed to the keyboard support portion at the front edge and the rear edge of the keyboard base.
In the meantime, each of Jpn. Pat. Appln. KOKAI Pub. No. 8-63260 (Prior Art IV), Jpn. Pat. Appln. KOKAI Pub. No. 2003-140770 (Prior Art V) and Jpn. Pat. Appln. KOKAI Pub. No. 2002-268774 (Prior Art VI) discloses a portable computer in which a character-inputting keyboard and a ten key pad are arranged on a top surface of a main body.
In each of Prior Arts IV to VI, a first mounting part and a second mounting part are formed on the top surface of the main body. The first and the second mounting parts are independent of each other. The first mounting part supports the keyboard, and the second mounting part supports the ten key pad.
According to Prior Art I–III, the keyboard base of the keyboard has a rectangular shape extending in the width direction of the main body, and left and right side edges each spread over the front edge and the rear edge. However, in the Prior Arts I to III, the keyboard is fixed by fixing only the front edge and the rear edge of the keyboard base to the keyboard support portion. Therefore, the left and right edges of the keyboard base are only placed on the keyboard support portion, not fixed thereto.
In conformity with reduction in thickness of the main body, the thickness of the keyboard base of the keyboard is reduced to minimum. Therefore, it is difficult to ensure stiffness of the keyboard base, and the keyboard base can deform to be warped in the width direction of the main body. Therefore, the conventional structure which fixes only the front and rear edges of the keyboard base causes the problem that the side edges of the keyboard base are raised apart from the keyboard support portion.
Further, according to Prior Arts IV to VI, it is necessary to provide the first mounting part for supporting the keyboard and the second mounting part for supporting the ten key pad separately from each other on the top surface of the main body. This complicates the structure of the main body, and causes increase in the cost of the portable computer. Furthermore, it inevitably increases the mounting parts for the keyboard and ten key pad onto the main body, and thus decreases the workability in mounting and removing the keyboard and ten key pad.